The selector switch has a conducting main lever, playing in a trough, similar to the latching switch, U.S. Pat. No. 4,128,749, with an open upward escape for ionized gas, which is brought about by arcing at any contact position of the switch. However, the selector switch has no single built-in sequence of connections, to be made and broken in feeding and disconnecting pieces of equipment. Instead, the present switch picks up a desired contact or a combination of contacts directly.
Existing lever switches allow stopping of the lever only in the two end positions of a lever run by lever catching contacts, shaped like receptacles, open only to one side, like a wedge hold. Contacts, fixed inbetween those end positions, cannot be massproduced with sufficient accuracy, to hold the lever, yet to let it pass through under increased forward pressure. Protruding parts of such contacts would stop the lever.
It has been proposed, to have in a latching switch (U.S. Pat. No. 4,128,749) a small built-in deviation of the lever run against its insulating trough way. However, on a very long trough way with many fixed contacts, at the ends of the lever run the latching bias may be excessive. The present selector switch uses a metallic main lever, long enough, to bend away from the contact lugs on its path for passing by. In order to pick up only one selected contact, a gate lever is designed. It can disconnect the pivot of the main lever, which pivot is built as a terminal, from the electrical source, while the main lever is being moved to a selected contact position.
When this position is reached, the operator closes the gate switch. A piece of equipment, connected permanently to the contact lug, against which the lever is resting with its conductive metal, receives current. The gate switch is designed to break contact under full load. For convenience, the gate switch is arranged in one corner of the lever run it is serving. Several parallel lever runs may be served at the same time.
The selector switch would not be fully operational without special fixed contacts, allowing in the confines of the trough a delicate adjustment of their free ends, without loosening the attachment of wires to the binding screws, screwed into the fixed contacts; their design and operation is described with reference to the drawing.
The invention is illustrated in the drawing, but not limited to the given examples, as substitutions for the conventional parts would not alter the spirit of the invention. Thus, locating the gate switch outside the housing of the selector switch would still fall within the general scope of the invention.